This invention relates to a mobile storage system for movably mounting storage units such as shelves or file cabinets, and more particularly to a wheel mounting arrangement for the carriage of such a mobile storage system.
High density mobile storage systems are commonly used when it is desired to increase the storage capacity in a given area greater that which is attainable using fixed shelving. A typical mobile storage system employs a series of mobile platforms or carriages to which storage units such as shelves or file cabinets are mounted, and which are movably supported on a series of parallel rails. The carriages extend across the rails, and a number of storage units are mounted to and movable with each carriage. By allowing the storage units to move, the aisle space normally required between storage units for access to the storage units may be eliminated for all but one pair of storage units. This single aisle space may be shared among pairs of storage units by movement of the storage units along the rails. The carriages are typically movable on the rails in response to operation of any satisfactory type of drive system associated with the carriages, for selectively creating an aisle between adjacent storage units so as to provide access to items stored in or on the storage units.
Certain known mobile storage systems employ a formed steel carriage that includes a series of wheel assemblies for moving the carriage along the rails. Each wheel assembly generally includes a wheel mounted to a shaft, and associated wheel bearings that are assembled to the formed sheet metal components of the carriage. A number of steps are involved in mounting each wheel assembly to the carriage, including securing the bearing assemblies to the carriage, positioning the wheel between the bearing assemblies, inserting the shaft through the bearings and the wheel, etc. In addition, in existing systems of this type, the load from the wheel is transferred to the carriage through the bearing and its bolted connection to the carriage. This construction applies significant loads to the bearings and the bolted connections, which can lead to excessive stress and premature failure of the bearings, carriage wheel assemblies, and/or the bearing connections under severe loads.
The present invention addresses these problems by providing a modular wheel assembly that can reduce the labor needed in assembly, as well as improve the carriage life and load carrying ability of the carriage. The modular wheel assembly of the present invention is configured to provide drop-in assembly to the carriage, which reduces the labor involved in initial assembly and also enables quick and easy replacement in the field. The modular wheel assembly is also configured to transfer the wheel load to the top of the carriage member in a manner that extends the operating life of the wheels and the carriage.
In accordance with the present invention, a carriage for a mobile storage system is adapted for placement over a rail, and is configured to support at least one storage unit for movement on the rail. The carriage generally includes a drive arrangement, a wheel mount structure, a shaft defining a pair of ends, a wheel mounted to the shaft, and first and second mounting members to which the shaft is rotatably mounted. The wheel is located between the first and second mounting members such that each end of the shaft extends outwardly from one of the first and second mounting members. The carriage further includes a cooperating mounting arrangement associated with the wheel mount structure and the first and second mounting members for non-rotatably mounting the first and second mounting members to the wheel mount structure. The cooperating mounting arrangement is configured such that the wheel extends downwardly from the wheel mount structure for engagement with the rail and the ends of the shaft extend outwardly from the wheel mount structure. One of the ends of the shaft engages the drive arrangement in a manner such that the drive arrangement imparts rotation to the shaft and to the wheel to move the carriage on the rail.
In one embodiment of the carriage, the wheel mount structure includes a structural member of the carriage having a first sidewall spaced from a second sidewall. The cooperating mounting arrangement generally includes an opening in each of the sidewalls and an engagement section associated with each of the first and second mounting members. Each engagement section is configured to be received within the opening in one of the first and second sidewalls of the structural member. Each of the first and second mounting members is secured to one of the first and second sidewalls of the structural member via one or more fasteners. Each of the first and second mounting members is adapted to be positioned within the space between the sidewalls of the structural member. The engagement section of each of the first and second mounting members extends outwardly into the opening of the first and second sidewalls. The structural member of the carriage further includes an upper wall that extends between and interconnects the spaced apart sidewalls. Each of the first and second mounting members includes an upper edge that engages an inner surface defined by the upper wall of the structural member. The fastener is located between the upper edge and the engagement section of each of the first and second mounting members. Each of the first and second structural member sidewalls defines a lower edge, and the opening in each of the first and second sidewalls extends upwardly from the lower edge. The engagement section of each of the first and second mounting members includes a rim that surrounds an opening through which the shaft extends. The rim and the opening in each of the first and second mounting members has a matching configuration that enables the rim to be received within the opening in the first and second sidewalls of the structural member. The shaft, the wheel, and the pair of mounting members generally comprise a wheel subassembly that is secured as a unit to the wheel mount structure. In one embodiment, the mounting members are in the form of bearing housings, each of which includes a bearing through which the shaft extends.
The invention also provides a method of mounting a wheel to a carriage of a mobile storage system. The carriage is configured to support one or more storage units for movement on a rail. The method includes the acts of providing a wheel mount structure with a first sidewall spaced apart from a second sidewall; forming an opening in each of the first and second spaced apart sidewalls of the wheel mount structure; providing a wheel assembly including a shaft, a wheel mounted to the shaft, and a first and a second mounting member to which the shaft is rotatably mounted, such that the wheel is located between the first and second mounting members; engaging each of the first and second mounting members within the opening in one of the first and second spaced apart sidewalls of the wheel mount structure; and securing each of the first and second mounting members to one of the first and second spaced apart sidewalls of the wheel mount structure.
The invention also provides a mobile storage system in which one or more storage units are carried by a carriage adapted to be movably supported on one or more rails. The carriage generally includes a wheel mount structure configured for placement over one of the rails. The mobile storage system includes a wheel subassembly for mounting a wheel to the wheel mount structure. The wheel subassembly includes a first and a second mounting member and a shaft that is rotatably supported by the first and second mounting members. The wheel is non-rotatably secured to the shaft between the first and second mounting members, and is positioned to engage one of the rails. The wheel mount structure and the first and second mounting members include a cooperating engagement structure for non-rotatably engaging the pair of first and second mounting members with the wheel mount structure.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.